Guessing for an average sized person of 80kg with around a 7.8m to 8m sail - around 12 knots.
With a 9m - around 11 knots and with a 10m around 10 knots.
Still a bit higher than a hydrofoil kitesurfing I think. Watched one of the top hydrofoil kitesurfers plane consistently last year in what looked like less than 10 knots.
A hydrofoil windsurfer planes a knot or two lower than a windsurfer with a big slalom board and the same sail size?
Watching the windsurfing hydrofoils their greater upwind and downwind angles seem to be their biggest advantage over a windsurfer and not their early planing.
The earliest planing windsurfer is a formula board with a 12.5m sail yeah? Well a foil can easily out perform that in terms of lower end and angle as seen at the last NSW state titles.
Realistically you need 8-10kts to start foiling but once foiling it can drop to 6tks or so and you can keep flying, a windsurfer can't hope to get near that. Need to turn around though and you're stuffed unless you get another gust.
The other thing I'd say that at 10-12kts on most windsurfers it's a battle. Maybe a formula board could plane but pretty much nothing else will. On a foil, you are hammering once it hits just that slightly higher windspeed.
Biggest sail I use is an 8.0m, 70kg though...and also one person's 10kts is probably not the same as the next person's 10kts.
10kts 7.3 sail I'm 112 to 115kgs and bye bye slappers and with big holes of under 8kts bye bye slappers !
Slappers....that's not very nice stroppo 
glad your having fun on the foils
i need to steal one of Noels and give it a go.
Yeah mate you sure do you don't wanna spend the rest of your life known as a slapper lol
I had my first go the other day, did a bit of crash n burn but was amazed how early it go going, I would never had got going in that wind on my slapper. Remember it's not just about how early you can get going, it's the buzz, it's fun and it's a new skill 
Select to expand quotefiriebob said..
Remember it's not just about how early you can get going, it's the buzz, it's fun and it's a new skill
What Firie said - and for me;
1) the amazing feeling of effortless gliding downwind on swells
2) awesome maneuverability
3) crazy upwind and downwind angles
4) turns chop into flat water - sail anywhere without getting thumped
5) fun in 10-15 knots without massive gear
86kg's, can get up with 7.0 severne unit singlecam, Lokefoil envol and JP135 pro in 8 knots. Purchased the new LK1 with 1200cm2 front wing and an 8.6 turbo to bring it down to 6kts. You need to learn how to pump without sailpreassure. I can get foiling when the water is flat (sometimes even when it's mirrorlike, when the leaves start russtling I go out), but I don't have enough wind to keep sustained flight (6-7kts) that's why I bought the bigger sail and frontwing. Now I find myself pumping up into the air and having to keep pumping to stay flying... Kind of annoying.
Select to expand quoteWhiteofHeart said..
86kg's, can get up with 7.0 severne unit singlecam, Lokefoil envol and JP135 pro in 8 knots. Purchased the new LK1 with 1200cm2 front wing and an 8.6 turbo to bring it down to 6kts. You need to learn how to pump without sailpreassure. I can get foiling when the water is flat (sometimes even when it's mirrorlike, when the leaves start russtling I go out), but I don't have enough wind to keep sustained flight (6-7kts) that's why I bought the bigger sail and frontwing. Now I find myself pumping up into the air and having to keep pumping to stay flying... Kind of annoying.
Any particular tips for pumping without sail pressure WOH?
Select to expand quoteMaddlad said..WhiteofHeart said..
86kg's, can get up with 7.0 severne unit singlecam, Lokefoil envol and JP135 pro in 8 knots. Purchased the new LK1 with 1200cm2 front wing and an 8.6 turbo to bring it down to 6kts. You need to learn how to pump without sailpreassure. I can get foiling when the water is flat (sometimes even when it's mirrorlike, when the leaves start russtling I go out), but I don't have enough wind to keep sustained flight (6-7kts) that's why I bought the bigger sail and frontwing. Now I find myself pumping up into the air and having to keep pumping to stay flying... Kind of annoying.
Any particular tips for pumping without sail pressure WOH?
Keep your weight forward, do small sail pumps to build up sailpreassure and get back with your front foot in the strap when you feel a little acceleration. Then pump hard on the foil. After I do this 2 times in really light winds I have trouble beathing :')
Select to expand quoteWhiteofHeart said..Maddlad said..WhiteofHeart said..
86kg's, can get up with 7.0 severne unit singlecam, Lokefoil envol and JP135 pro in 8 knots. Purchased the new LK1 with 1200cm2 front wing and an 8.6 turbo to bring it down to 6kts. You need to learn how to pump without sailpreassure. I can get foiling when the water is flat (sometimes even when it's mirrorlike, when the leaves start russtling I go out), but I don't have enough wind to keep sustained flight (6-7kts) that's why I bought the bigger sail and frontwing. Now I find myself pumping up into the air and having to keep pumping to stay flying... Kind of annoying.
Any particular tips for pumping without sail pressure WOH?
Keep your weight forward, do small sail pumps to build up sailpreassure and get back with your front foot in the strap when you feel a little acceleration. Then pump hard on the foil. After I do this 2 times in really light winds I have trouble beathing :')
Haha I can understand that, we went out today and I'm absolutely shattered from pumping up on the plane. :P
Slappers! Love it.
best excuse for getting a foil is getting away from those Slapper knees. No slap no pain.
speed to get up on foil is board speed not wind speed. This is what creates lift. Pumping is all about building speed through water.
pumping the foil as in that up and down movement is also about speed as you push down you speed up foil through water but with a momentary increase in AoA.
Once that draggy Slapper thing on top of foil is released from water then worry about wind speed.
We foiled yesterday in Hobart in 10 knots gusting to 12. We able to pump the board up onto the foil and then glide. Had 6m wave sails. After an hour, the wind dropped to 8-10 knots and we couldn't pump onto the foil, so probably needed bigger sails. I'm 70kg and have the Naish windfoil. My mate has the Slingshot and he is about 75kg. As CJW suggested, if there's a gust you can get up and going, then sail in the lighter winds. But if there's no gusts, you may find yourself dogging back in. For pumping, we have found pointing the nose off the wind and light pumps of the sail to get momentum. Then as the momentum builds, pump the sail a bit harder, move front foot back into the strap, kick against the foil with the back foot to develop lift and it should start to pop up.
Select to expand quoteMaddlad said..WhiteofHeart said..
86kg's, can get up with 7.0 severne unit singlecam, Lokefoil envol and JP135 pro in 8 knots. Purchased the new LK1 with 1200cm2 front wing and an 8.6 turbo to bring it down to 6kts. You need to learn how to pump without sailpreassure. I can get foiling when the water is flat (sometimes even when it's mirrorlike, when the leaves start russtling I go out), but I don't have enough wind to keep sustained flight (6-7kts) that's why I bought the bigger sail and frontwing. Now I find myself pumping up into the air and having to keep pumping to stay flying... Kind of annoying.
Any particular tips for pumping without sail pressure WOH?
Very sort pumps. Put your hands either side of you harness lines and start really small. As the foil begins to generate lift start to extend and rotate the pump
Select to expand quotepetermac33 said..
Guessing for an average sized person of 80kg with around a 7.8m to 8m sail - around 12 knots.
With a 9m - around 11 knots and with a 10m around 10 knots.
Still a bit higher than a hydrofoil kitesurfing I think. Watched one of the top hydrofoil kitesurfers plane consistently last year in what looked like less than 10 knots.
A hydrofoil windsurfer planes a knot or two lower than a windsurfer with a big slalom board and the same sail size?
Watching the windsurfing hydrofoils their greater upwind and downwind angles seem to be their biggest advantage over a windsurfer and not their early planing.
No way!!
6.3 in 10 knots (NP F4 big wing) I have to pump to fly but will maintain it as long as I stay on the foil. Im 86kgs. I have been out on the Np F4 Small wing on my 6.3 in 12 knots and once flying it's a dream. Super slippery. Just have to maintain speed. No different to your SLAPPER kit when you drop off the plane, it takes effort to get back on the fin.
